406 G. R. CROTCH, M. A. 



% anterior external claw sinuate at base, anal segment deeply emarginate. 

 Greenland; also recorded from Lapland by Thomson. 

 G. Drewseni is founded on an abnormal specimen having the sides 

 of the thorax rounded and sinuate bofore the anterior angles. 



CYHf ATOPTERUS, Esch. Dej. Cat., p. 61. (Type Paykulli.) 



Closely allied to Golymbetes, from which it differs by the male tarsi, 

 which are less broadly dilated and have no discs beneath, the anal seg- 

 ment has a rounded emargination. 



C. longulus, (Lee.) Proc. Phil. (1862), p. 522, 12.— Elongate ovate, hardly 

 dilated behind, entirely black beneath; front of head and sides of thorax ful- 

 vous, elytra with the margins fulvous, disc darker, finely transversely strigose 

 posterior femora strigulose, tibiae with one deep row of punctures, and sparing 

 ly punctulate besides. L. -6S inch. 



Lake Superior, Kansas. 



Apparently identical with C. Paykullii of Europe, but I have not 

 seen the male. 



C. obsciiratus, (Mannh.) Bull. Mosc. (1853) iii.,p. 154; (Lec.)l. c. p. 522, 

 10. — Very nearly allied to C. longulus, from which it is distinguished by its 

 larger size and by the elytra dilated bebind the middle. L. -74 inch. 



Kadjak. 



The single 9 before me is entirely opaque and has the sides of the 

 thorax rounded and sinuate before the anterior augles which are 

 acutely produced ; this structure (not noticed by Mannerheim), I am 

 inclined to consider abnormal. 



The species is very nearly allied to G. Paykullii, of Europe, or da- 

 Imria of Siberia. 



C seminiger, (Lee.) 1. c. p. 522, 11. — Resembling C. longulus, in form, 

 black beneath, humeral angle of epipleurse fulvous, thorax fulvous with a 

 transverse median bar black; elytra as in C. longulus. L. *74 inch. 



% anterior external tarsal claw rounded at apex deeply sinuate at base. 



Saskatchewan. 



C insequalis, Horn, Tr. Am. Ent. Soc. iii., 330.— 9 • — Extremely close to 

 C. seminiger, from which it only differs by the entirely yellow epipleurse of the 

 elytra. L. - 74 inch. 



In a warm spring near Susanville, California. (Horn.) 

 The four specimens before are all females and agree in having the 

 elytra opaque for two-thirds their length, the apex shining. 



DYTISCUS, Linn. 1735. (Type marginalis.) 

 This genus is equally represented in Europe, but the most northern 

 European species (Z>. lapponicus) does not pass over. The most re- 

 markable fact is the prevalence of smooth females; in England, of six 



